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Automatic appliances for sewage works
May, 1901]
Analytical Notes
591
necessary a little ether, and titrates the solution in the usual way. The ratio thus obtained between the value for the soluble volatile aoids varies greatly in different fats, the difference being most marked between butter and cocoanut oiL--Analyst. ADULTERATION OF I~OASTED COFFEE BY TREATMENT WITH BORAX AND
WATEr. E. BERTAI~ELLI(Zeit. fiir Untersuch. der .~ahr. q~ndGen~ss,nittel, 1900, iii., 681-683).--The author calls attention to the adulteration of roasted coffee-beans by the practice of pouring aqueous solution of borax over them. The solution is readily absorbed by the beans, causing an increase of about 12 per cent. in their weight, and renders them glossy in appearance, without at all impairing their original hardness. Borax should be looked for in cases where 4 per cent. or more of water is found ; whereas genuine roasted coffee does not usually contain more than about 3 per cent. of water, the author has found upwards of 10 per cent. in roasted beans which have been treated in the way
described.--Analyst.
THE ESTIMATION OF URIC ACID. A. ]3ELLOCQ (JourTu 2harm. Chim., 1900, xii., 103, 104).--To 250 e.c. of the urine under ex-
amination is added an excess of sodium hydroxide solution, the precipitate allowed to subside, and the supernatant liquid decanted, shaken with asbestos powder and filtered. To 200 e.c. of the filtrate are added 20 c.e. (or more if required) of a reagent consisting of--zinc sulphate solution (1 : 3), 30 c.c. ; sodium hydroxide solution, 30 c.c.; and sodium carbonate solution (saturated), 40 c.c. The voluminous precipitate is collected on a filter and drained. I t is next detached from the paper and dried in a porcelain crucible, into which are then introduced 2 or 3 c.e. of hydrochloric acid saturated with pure uric acid. The crucible is allowed to float on the surface of cold water, and the uric acid crystals which deposit are collected, washed with 10 c.c. of alcohol, dried and weighed.--Analyst.
AUTOMATIC APPLIANCES FOR SEWAGE WORKS. IN our issue for May, 1900,* D r . Garstang gave an account of some experiments which he had made for the disposal of sewage at Hale. H e spoke very highly of a distributing mechanism devised b y Mr. l~idgway. The description given appeared to us to be somewhat incomplete, but we were unable at that time to obtain fuller details. We are now able to give a full description of the " Ridgway" distributor from information supplied by Messrs. Mather and Platt, Ltd., of Manchester. We do not pronounce any opinion, leaving our readers to refer to Dr. Garstang's paper to ascertain his view, based on actual working. The sewage is received at A (see Fig. I.) into a syphon chamber, constructed to contain and deliver a given quantity determined by the total bulk of sewage to be dealt with. When the chamber is full, the syphon ]3 discharges the sewage in the syphon chamber into the distributing chamber at D. In so doing, the hollow cylindrical float C (which has been previously raisedby the filling of the chamber) descends, and by a pawl and ratchet-wheel causes the shaft E to move through a fraction of a complete revolution, according to the number of separate "Practical Results of Experiments in Sewage Treatment/~ PUBLICHEALTHy
xii., p. 612.
592
Appliances for Sewage Works
t~'~b~ca~m
filter beds to be fed. By an arrangement of cams on the shaft, and levers on the valves F, one of these valves, which had been held open since the last discharge, is released, and falls by i~s own weight, thus closing that particular aperture to the sewage in the distributing chamber; and, simultaneously, the next valve in sequence is raised, so ~hat the sewage flows through a different outlet to that used at the previous discharge. The sewage from the main outfall sewer is thus distributed in measured quantities by different outlets in rotatAon. This action wilt continue automatically, and requires almost no attention. When a second contact-bed is used, it is dependen~ entirely upon the first contact-bed for its supply of effluent. In the first bed, the accelerated velocity given to the sewage by the action in chamber B causes the sewage to be to some extent forced from the distributing pipes over the surface of the bed, but there is no such flush to assis~ in the distribution from the first to the second contact-bed. The required velocity, however, from the first to the second bed c~u be obtained by means of a patent automatic retaining and flushing valve, which is arranged to retain a certain specified head of effluent, and to discharge the same at
I~IG, I.
a given time. This apparatus will cause the sewage to be kept in contact with the first bed 'for any required length of time. The distribution of the e~uent over the second contacVbed is perfectly accomplished by this method. The automatic retaining and flushing valve is very simple in construction, ai~d is actuated by the flow of the sewage. The machinery described can be applied t o filters constructed on Dibden's principle, with the addition of a special arrangement for opening outlet valves. Its mechanism is easily understood from the two blocks (Figs. I[. and III.). Fig. II. shows the valve close~ and the liquid passing through the overflow pipe ]~ into the float. Fig. I I L shows the valve open and the contents A being rapidly discharged. The manner of i~s operation is as follows : When the water in the chamber A rises to the level shown in the drawing, it flows through the pipe F and gradually fills the float-tank B. By the time this is at a given height, the weight of the water is sufficient to lift the valve flap C a little off its seating D. The water then flows through the valve into the float-bottom E. This extra weight
~ay, l~l~
Appliances for Sewage W o r k s
593
opens the valve fully and immediately, and the water rushes away into the chamber G. The water in the float4ank B escapes through an outlet provided for the purpose, and when the float is empty the valveflap (being heavier than the floa.t) falls down on its seating, and ¢ahe valve is again closed.
~4
~2
The time during which the valve is closed for " holding in contact," and the time the valve is held open, depend upon the time occupied in filling and emptying the float. These two operations can be regulated to the utmost nice~y, and thus the entire system is under the most complete control. The action of the valve is efl'ected by the flow of the sewage, and
594
Appliances for Sewage Works
t~b~e aealth
automatically adjusts i~self to the constantly varying volume of sewage, thus maintaining (in conjunction with t h e " Ridgway" Patent Automatic Distributor) the systematic feeding of the beds in regular succession. The valves being set at the outset for a certain volume of sewage, and a given number of cycles per diem, any increase or decrease in the flow
b-4 F-4
will cause a corresponding change in the number of cycles without any manual operations whatever. The advantages claimed for the valve are, amongst others, ~he following : 1. It can be regulated to discharge the contents of ~he bacteria beds as desired.
May, ~9o1~
Appointments
595
2. During the period that the bed is becoming matured, the discharge can be diminished, and the bacteria thereby kept in a state of quiescence. 3. When the bed has become matured, the discharge can be increased to ~he full capacity of the valve. 4. There is n o suction to disturb the bacterial action, the sewage flowing out by gravitation only. 5. There is only one moving part, namely, a delta metal hinge. 6. No fall is taken up ; if working " double contact" the surface of the second bed can be constructed on a level with the outlet of the first. These are very important advantages in carrying out an efficient system of sewage purification. For flushing intermitten~ doses on bacteria beds, when such are worked as continuous beds and not held in contact, the valve can be so arranged as ~o deliver any given quantity (or in a fixed time), thus dividing the flow alternately over any number of beds automatically, and delivering any given number of gallons per day (based on ~he normal flow), so preventing any one bed having more than its share.
APPOINTMENTS. Allinson, H. C., M.B.C.S., appointed M.O.H. of King's Lynn Municipal Borough. Benson, P. L., M.D., re-appointed M.O.t/[. of Buckingham Rural Sanitary District. Bond, F. T/., M.D., re-appointed M.O.tL of Cirencester and Chipping Sodbury l~ural Sanitary Districts. Bostock, A. S., M.R.C.S., re-appointed M.O.H., Westhampnett Rural Sanitary District. C h a r p e n t i ~ r , A. E. L., M.B., appointed M.O.H. of Uxbridge Rural Sanitary District. Collingridge, W., M:/), appointed M.O.H. of City of London. C r o c k e r , 0. H., M.D., appointed M.O.H. of Richmond Municipat Borough. Crookshank, Fi G., M.D., appointed M.O.H. of Barnes Urban Sanitary District. Cross, R. G., LR.C.P., appointed M.O.H. of Petersfield Rural Sanitary District. Eaton, 0., M.B.C.S., re-appointed M.O.tt. of Grantham Rural Sanitary District. Eglinton, G. W., L.R,C.P., appointed M.O.H. of \Veils (Somersetshire) Rural Sanitary District. G r e e n w o o d , A., M.D., re-appointed M.O.tt. of Crewe Municipal Borough. Halford, A. C. F., M.D., appointed M.O.H. of City of Brisbane, Queensland. H a m i l t o n , W. M., M.D., appointed M.O.H. of Eecles Municipal Borough. Hill, P. E., M.R.C.S., =appointed M.O.H. of Criekhowell Combined Sanitary Distciet.
Analytical Notes
591
necessary a little ether, and titrates the solution in the usual way. The ratio thus obtained between the value for the soluble volatile aoids varies greatly in different fats, the difference being most marked between butter and cocoanut oiL--Analyst. ADULTERATION OF I~OASTED COFFEE BY TREATMENT WITH BORAX AND
WATEr. E. BERTAI~ELLI(Zeit. fiir Untersuch. der .~ahr. q~ndGen~ss,nittel, 1900, iii., 681-683).--The author calls attention to the adulteration of roasted coffee-beans by the practice of pouring aqueous solution of borax over them. The solution is readily absorbed by the beans, causing an increase of about 12 per cent. in their weight, and renders them glossy in appearance, without at all impairing their original hardness. Borax should be looked for in cases where 4 per cent. or more of water is found ; whereas genuine roasted coffee does not usually contain more than about 3 per cent. of water, the author has found upwards of 10 per cent. in roasted beans which have been treated in the way
described.--Analyst.
THE ESTIMATION OF URIC ACID. A. ]3ELLOCQ (JourTu 2harm. Chim., 1900, xii., 103, 104).--To 250 e.c. of the urine under ex-
amination is added an excess of sodium hydroxide solution, the precipitate allowed to subside, and the supernatant liquid decanted, shaken with asbestos powder and filtered. To 200 e.c. of the filtrate are added 20 c.e. (or more if required) of a reagent consisting of--zinc sulphate solution (1 : 3), 30 c.c. ; sodium hydroxide solution, 30 c.c.; and sodium carbonate solution (saturated), 40 c.c. The voluminous precipitate is collected on a filter and drained. I t is next detached from the paper and dried in a porcelain crucible, into which are then introduced 2 or 3 c.e. of hydrochloric acid saturated with pure uric acid. The crucible is allowed to float on the surface of cold water, and the uric acid crystals which deposit are collected, washed with 10 c.c. of alcohol, dried and weighed.--Analyst.
AUTOMATIC APPLIANCES FOR SEWAGE WORKS. IN our issue for May, 1900,* D r . Garstang gave an account of some experiments which he had made for the disposal of sewage at Hale. H e spoke very highly of a distributing mechanism devised b y Mr. l~idgway. The description given appeared to us to be somewhat incomplete, but we were unable at that time to obtain fuller details. We are now able to give a full description of the " Ridgway" distributor from information supplied by Messrs. Mather and Platt, Ltd., of Manchester. We do not pronounce any opinion, leaving our readers to refer to Dr. Garstang's paper to ascertain his view, based on actual working. The sewage is received at A (see Fig. I.) into a syphon chamber, constructed to contain and deliver a given quantity determined by the total bulk of sewage to be dealt with. When the chamber is full, the syphon ]3 discharges the sewage in the syphon chamber into the distributing chamber at D. In so doing, the hollow cylindrical float C (which has been previously raisedby the filling of the chamber) descends, and by a pawl and ratchet-wheel causes the shaft E to move through a fraction of a complete revolution, according to the number of separate "Practical Results of Experiments in Sewage Treatment/~ PUBLICHEALTHy
xii., p. 612.
592
Appliances for Sewage Works
t~'~b~ca~m
filter beds to be fed. By an arrangement of cams on the shaft, and levers on the valves F, one of these valves, which had been held open since the last discharge, is released, and falls by i~s own weight, thus closing that particular aperture to the sewage in the distributing chamber; and, simultaneously, the next valve in sequence is raised, so ~hat the sewage flows through a different outlet to that used at the previous discharge. The sewage from the main outfall sewer is thus distributed in measured quantities by different outlets in rotatAon. This action wilt continue automatically, and requires almost no attention. When a second contact-bed is used, it is dependen~ entirely upon the first contact-bed for its supply of effluent. In the first bed, the accelerated velocity given to the sewage by the action in chamber B causes the sewage to be to some extent forced from the distributing pipes over the surface of the bed, but there is no such flush to assis~ in the distribution from the first to the second contact-bed. The required velocity, however, from the first to the second bed c~u be obtained by means of a patent automatic retaining and flushing valve, which is arranged to retain a certain specified head of effluent, and to discharge the same at
I~IG, I.
a given time. This apparatus will cause the sewage to be kept in contact with the first bed 'for any required length of time. The distribution of the e~uent over the second contacVbed is perfectly accomplished by this method. The automatic retaining and flushing valve is very simple in construction, ai~d is actuated by the flow of the sewage. The machinery described can be applied t o filters constructed on Dibden's principle, with the addition of a special arrangement for opening outlet valves. Its mechanism is easily understood from the two blocks (Figs. I[. and III.). Fig. II. shows the valve close~ and the liquid passing through the overflow pipe ]~ into the float. Fig. I I L shows the valve open and the contents A being rapidly discharged. The manner of i~s operation is as follows : When the water in the chamber A rises to the level shown in the drawing, it flows through the pipe F and gradually fills the float-tank B. By the time this is at a given height, the weight of the water is sufficient to lift the valve flap C a little off its seating D. The water then flows through the valve into the float-bottom E. This extra weight
~ay, l~l~
Appliances for Sewage W o r k s
593
opens the valve fully and immediately, and the water rushes away into the chamber G. The water in the float4ank B escapes through an outlet provided for the purpose, and when the float is empty the valveflap (being heavier than the floa.t) falls down on its seating, and ¢ahe valve is again closed.
~4
~2
The time during which the valve is closed for " holding in contact," and the time the valve is held open, depend upon the time occupied in filling and emptying the float. These two operations can be regulated to the utmost nice~y, and thus the entire system is under the most complete control. The action of the valve is efl'ected by the flow of the sewage, and
594
Appliances for Sewage Works
t~b~e aealth
automatically adjusts i~self to the constantly varying volume of sewage, thus maintaining (in conjunction with t h e " Ridgway" Patent Automatic Distributor) the systematic feeding of the beds in regular succession. The valves being set at the outset for a certain volume of sewage, and a given number of cycles per diem, any increase or decrease in the flow
b-4 F-4
will cause a corresponding change in the number of cycles without any manual operations whatever. The advantages claimed for the valve are, amongst others, ~he following : 1. It can be regulated to discharge the contents of ~he bacteria beds as desired.
May, ~9o1~
Appointments
595
2. During the period that the bed is becoming matured, the discharge can be diminished, and the bacteria thereby kept in a state of quiescence. 3. When the bed has become matured, the discharge can be increased to ~he full capacity of the valve. 4. There is n o suction to disturb the bacterial action, the sewage flowing out by gravitation only. 5. There is only one moving part, namely, a delta metal hinge. 6. No fall is taken up ; if working " double contact" the surface of the second bed can be constructed on a level with the outlet of the first. These are very important advantages in carrying out an efficient system of sewage purification. For flushing intermitten~ doses on bacteria beds, when such are worked as continuous beds and not held in contact, the valve can be so arranged as ~o deliver any given quantity (or in a fixed time), thus dividing the flow alternately over any number of beds automatically, and delivering any given number of gallons per day (based on ~he normal flow), so preventing any one bed having more than its share.
APPOINTMENTS. Allinson, H. C., M.B.C.S., appointed M.O.H. of King's Lynn Municipal Borough. Benson, P. L., M.D., re-appointed M.O.t/[. of Buckingham Rural Sanitary District. Bond, F. T/., M.D., re-appointed M.O.tL of Cirencester and Chipping Sodbury l~ural Sanitary Districts. Bostock, A. S., M.R.C.S., re-appointed M.O.H., Westhampnett Rural Sanitary District. C h a r p e n t i ~ r , A. E. L., M.B., appointed M.O.H. of Uxbridge Rural Sanitary District. Collingridge, W., M:/), appointed M.O.H. of City of London. C r o c k e r , 0. H., M.D., appointed M.O.H. of Richmond Municipat Borough. Crookshank, Fi G., M.D., appointed M.O.H. of Barnes Urban Sanitary District. Cross, R. G., LR.C.P., appointed M.O.H. of Petersfield Rural Sanitary District. Eaton, 0., M.B.C.S., re-appointed M.O.tt. of Grantham Rural Sanitary District. Eglinton, G. W., L.R,C.P., appointed M.O.H. of \Veils (Somersetshire) Rural Sanitary District. G r e e n w o o d , A., M.D., re-appointed M.O.tt. of Crewe Municipal Borough. Halford, A. C. F., M.D., appointed M.O.H. of City of Brisbane, Queensland. H a m i l t o n , W. M., M.D., appointed M.O.H. of Eecles Municipal Borough. Hill, P. E., M.R.C.S., =appointed M.O.H. of Criekhowell Combined Sanitary Distciet.