HomeMy WebLinkAboutApproving a Contract Between Wastewater Treatment Plant E.R. Knapp & Co Amount $258,385.00ORDINANCE No. 5097 -69
Passed by the Common Council of the City of South Bend,
August 11, �9 69
Presented by me to the Mayor of the City of South Bend,
Approved and signed by
August 12, 19 69
City Clerk
of Common Council
Clerk
IDEAL tOJEWPRESS
ORDINANCE NO. 5097 -69
AN ORDINANCE APPROVING A CONTRACT BETWEEN THE
WASTEWATER TREATMENT PLANT OF SOUTH BEND,
INDIANA AND E. R. KNAPP & COMPANY, ROCHESTER,
INDIANA, FOR CONSTRUCTION AND INSTALLATION OF
GAS MIXING EQUIPMENT MANUFACTURED BY RALPH B.
CARTER COMPANY IN THE TOTAL AMOUNT OF $258,385.00.
BE IT ORDAINED BY THE COMMON COUNCIL OF THE CITY OF SOUTH BEND,
INDIANA:
SECTION I: That the contract entered into between the Wastewater
Treatment Plant and E. R. Knapp & Company, Rochester, Indiana, on
the 21st day of July 1969, pursuant to advertising and receipt of
bids, as the construction and installation is necessary in the opera-
tion of said Wastewater Treatment Plant, is hereby approved and
confirmed.
SECTION II: This Ordinance shall be in full force and effect from
and after its adoption and approval by the Mayor.
1st & 2nd READING 7 -76 -69
COMMITTEE OF THE WHOLE 8 -11 -69
PUBLIC HEARING 8 -11 -69
3rd READING8 -11 -69
NOT APPROVED
REFERRED
PASSED 8 -11 -69
M mbed r of the Common Council
iN CLERK'S ULL -
JUL 2 4 1969
';ATHRYN L. BLOUGH
7Y CLERK, SOUTH BEND, IND:
0
July 23, 1969
TO: Members of the Common Council
RE: Gas Mixing Equipment - Wastewater Treatment Plant
FROM: John L. Hunter, Superintendent of Utilities
The proposed Ordinance for $258,385 is for the necessary construc-
tion, installation work, and gas mixing equipment to be done by E. R.
Knapp &,.Company. We are attaching the report submitted by Clyde E.
Williams & Associates, Incorporated, showing the analysis of bids,
description and comparisons of the two systems which were bid, cost
comparisons and recommendations. This will give you the "why's" on
the bids and the systems. This system is needed to improve our digesters
which are deficient in heating and mixing of sludge in this area. It
conforms to our overall improvement plan for the plant as outlined in
Clyde E. Williams' report of 1965.
Due to the complexity of the program, we would appreciate the
time necessary to explain the systems in more detail. We will be pleased
to answer any questions necessary to satisfy yourselves that this is a
needed improvement to our plant.
Enclosures
n�
John L. Hunter
r J ERK'S OV .
JUL 2 4 1969
'CATHRYN L. BLOUSH
Y CLERK, SOUTH BEND, IND.
CITY OF SOUTH BEND
REPORT ON GAS MIXING & HEATING
EQUIPMENT FOR TWO (2) DIGESTER
Analysis of Bids
Low Bid based on Alternate "A" as
submitted by E. R. Knapp & Co.,. -_$
Rochester, Indiana--------------------------------
Low Bid based on Alternate "B" as
submitted by C & C Construction 'Co. , - -$ 3 °,
Fort Wa ne,. Indiana---------- -- --- --- ----'-- - -' - --
Difference between lowest bids based
on low for Alternate "A" and low for 7 Z 6
Alternate " B,'---------------------- ---- -------- - -= - -$
Description & Comparison of Two Systems:
Alternate "A" Under Alternate . "A ",.the gas mixing equip-
ment is as manufactured by Ralph B. Carter Company and is the patented
full bore expendable piston type bubble, introducing a minimum amount
of gas into the mass of sludge in order to produce a maximum turnover,
pumpage. Approximately 7.5 c.f.m. divided by 0.54 (Volume of piston
bubble) = 14 pulsations per minute in a 12" tube pumping approximately
1400 g.p.m.:with a tube velocity of 4 feet per second.
Six 12" diameter tubes each equipped with expendable piston
bubble type guns will be installed in each roof. For mixing without
heating one compressor is used which operates two guns (Pumping rate+
2800 g.p.m.), then two more guns in sequence and finally the other two
guns until all six guns have been operated in sequences, completely
around the digester. The normal horsepower requirement for gas mixing
being two .(2) horsepower. For heating all six guns are operated si-
multaneously with a total requirement of 5.,horsepower per digester.
The bubble producer is like a cone fulcrum set into inverted
cylinder. The size of opening for discharge of bubble being approxi-
mately 2- 1/2 ".. Plugging or malfunction is extremely unlikely.
Alternate "B" - Alternate "B" the gas mixing equipment is as
manufactured by P.F.T. as is described as the "Pearth" system. Under
this system,.approximately 300 c.f.m. is injected into a vertical 1 -1/2"
diameter pipe (called a lance). On the sidewalls and near the lower
end a number of small holes are drilled to let the compressed gas
release.carrying upward with it a flow.- This system is an unrefined
air lift of tthe an inefficient type,but should provide a pumpage rate'
as high or higher than the Carter aero -gun.
COMPARISONS
(Carter)
Aero -Gun
1) Six separate motorized gas
valves (one for each gun)
Class 1, Div.l Explosion
proof. Any one valve may
be isolated or malfunction
but will not interfere with
the others.
2) Two compressors (2 h.p. &
3 h.p.) are provided for
each digester. System can
function with one compres-
sor under malfunction.
3) Piston bubble checked as
operational since 1963 as
maintaining a bubble as
providing 3.5 to 4 f.p.s.
velocities entirely through-
out the pipe heating barrel
to ensure cleansing velocity
and inhibit caking under
heating conditions.
4). Two flame traps and flame
check provided to protect
all gas lines from compres-
sor area to roof.
5) steel, corrosion
proof materials in pressure
gauges,.and regulators.
6) Suction line to gas dome
low velocity self- draining
type
(P.F.T.)
Pearth
1) One -only rotary valve in
which a malfunction means
all gas mixing tubes are
affected by the malfunction.
2) One compressor (25 h.p.)
provided for each digester.
System is inoperative if
compressor malfunctions.
3) Indiscriminate emission of
bubbles providing poor
assurance of cleaning velocity
throughout pipe heating barrel.
4). One flame arrestor on suction
line only.
5) Appears to be standard bronze
elements.
6) Suction line to gas dome drip -
pot type, high velocity (pos-
sibly could draw in-air if a
leak occuried).
COST COMPARISON
Higher capital cost of Alternate "A"
over Alternate "B " ---------------- $19,726.00
ANNUAL COST OF ALTERNATE "A" FOR
ADDITIONAL INVESTED MONEY: AND
ELECTNIM POWER:
Assume lost. of interest of invested
funds 5% per annum on $ 19,726.00 -------------- ------- $
(H.P. in winter = 80% of 10 =.8 H.P. for
five months = .8 x5 - 40 H.P. months in
spring, fall, and summer =.30% of 10 =
3 x7 = 21 H.P. months)
61 H.P. months
K.W.H.'s = (61) (.746) (2.4) (30).= .
32,600
986.00
Annual Power ' Cost.@. 14/ K .W.H.----------------- --- --- --- 326.00
TOTAL ANNUAL COST $ 1,306.00
ANNUAL COST OF ALTERNATE "B" FOR
ELECT" fG; POWER
50 H.P. running. continuously K.W.H.'s =
(50) (.346) (24) (365) = ,325,000
Annual Power Cost @ 1 <2/ K.W.H.-------- ----- --- --------- $ 3,250.00
Annual Savings by Selecting Alternate "A"
Aero - Hydraulic by Carter Company------------- - - - - - -- $ 1,944.00
Comments & Rdcommendations
Alternate "A"
Telephone calls were made to verify the Carter principle,
the conclusions being that the piston bubble is as ciaimedr; and rela-
tively trouble free. The equipment is of superior construction and
design and has a factor':' of reliability of 4:1 on the compressors
and 6:1 on the gas system over "Pearth" by P.F.T.
We recommend the "Carter: aero- hydraulic system as being
a satisfactory system of superior construction, reliability, less
maintainence and much cheaper to operate. The difference in initial
capital cost is more than justified.
Inspection Trip & Conclusion
A trip was made to "St' kne &.Hanover" Plants in Chicago
by Mr. Louis Rague, Mr. Casimir Bp,and the writer. Though
not yet operating at Chicago, the aero -guns by Carter were visually
inspected as to construction and principle including compressors and
components.
The Pearth System, in operation in Chicago have caused
considerable trouble in operation. The main trouble being high froth -
ing which has forced sludge out and up around the floating covers.
This problem in winter with freezing conditions has been quite serious.
To minimize the problem,.the 15' lances were cut to 51. This did not
cure the problem, but did reduce it. Now this system can only dis-
turb the top surface of the digester and does not perform the service
for which it was intended. The apparent cause of this frothing ap-
pears to be pumping such high volumes of gas through the sludge media
and stripping therefrom foaming elements. We recommend against the
Pearth System, which in our opinion has a far greater hazard in opera-
7E lacks in reliability, and has a high operational cost.
CLYDE E. WILLIAMS & ASSOCIATES, INC.
Bernard E. Brennan
fdIIUtritl# u Itpart August 11, 1969
Xv 24c Tomm u Mouncil of Up Cug of £►mall Jktux
Your Committee of the Whole
to whom was referred
AN ORDINANCE APPROVING A CONTRACT BETWEEN
THE WASTEWATER TREATMENT PLANT OF SOUTH BEND,
INDIANA AND E. R. KNAPP & COMPANY, ROCHESTER,
INDIANA, FOR CONSTRUCTION AND INSTALLATION
OF GAS MIXING EQUIPMENT MANUFACTURED BY
RALPH B. CARTER COMPANY IN THE TOTAL AMOUNT
OF $258,385.00.
Respectfully report that they have examined the matter and that in their opinion the Ordinance go to
the Council as favorable.
William W. Grown s
Chairman