SECTION 11___
CHLORINE DIOXIDE GENERATING EQUIPMENT
PART 1
1.01
1.02
GENERAL
DESCRIPTION
A.
This document covers the equipments and materials necessary to install
and operate a chlorine dioxide generator. The system, as specified herein,
shall be a compact pre-mounted generation and dosing system for
chlorine dioxide according to sodium chlorite / hydrochloric acid method
with chemicals-saving and 1:1 mixing ratio. A batch tank for final product
storage and feed shall be integrated in to the generator system.
B.
The chlorine dioxide generator shall use dilute concentrations of
chemicals for generation; 7.5% sodium chlorite and 9% hydrochloric acid.
C.
Each generator shall have a maximum capacity of [5 g/h, .26 lb/day] [10
g/h, .54 lb/day] [30 g/h, 1.6lb/day] [60 g/h, 3.12 lb/day].
D.
Each generator shall be Grundfos / Alldos Oxiperm OCD 162.
MANUFACTURER
A.
Manufacturer shall submit proof of the following qualifications.
a. The manufacturer is the actual manufacturer of the equipment being
supplied.
b. The Manufacturer has successfully designed and manufactured similar
equipment for at least 5 years.
c. The Manufacturer has the required financial capability.
d. The Manufacturer maintains a qualified technical engineering staff and
design office.
e. The Manufacturer operates a physical plant and employs fabricating
personnel to complete the work specified.
f. The Manufacturer shall maintain competent service personnel to
service the equipment furnished.
g. The unit shall be manufactured by Grundfos Pumps Corporation or
equal
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Project Name
11___-1
Project No.
B.
PART 2
The manufacturer or authorized factory representative shall conduct a preinstallation site inspection of the application to ensure the proper
application of all chlorine dioxide generating equipment and associated
systems and controls.
PRODUCT
2.01 GENERATION
A.
Capacity: The generator shall generate up to _____ grams/hour of
chlorine dioxide solution, the chlorine dioxide concentration shall be 2.0
mg/L.
B.
Chemical usage: the generator shall use diluted hydrochloric acid (9%)
and diluted sodium chlorite solutions (7.5%), The system is equipped with
microprocessor control to inject process water, hydrochloric acid and
sodium chlorite consecutively in to the generator chamber. Feed of the
chemicals are verified through integrated level sensors.
C.
Production: the generator will produce chlorine dioxide solutions in to an
integrated batch overflow tank, and feed the solution with an integrated
feed pump [continuously into the process as required by the controls] [in
batch generation as required to maintain a constant chlorine dioxide batch
tank reservoir between preset volume levels].
D.
Electric Power: The generator shall operate at 115 Volt / 60 Herz / Single
phase or 220 Volt / 60 Herz / Single phase.
E.
Chlorine dioxide solution delivery: The generator shall include a
distribution pump included in the generator box system, controlled directly
via the generator controller, or independently-controlled; the distribution
pump is capable of delivering chlorine dioxide solution against 145 PSI
pressure using an internal stepper motor. Solenoid driven pumps are not
acceptable.
a. The pumps shall have PVDF head materials with PTFE gaskets and
diaphragm and capable of a 4-20mA analog or digital contact control
signal and a 4-20mA analog output signal.
b. The distribution pumps shall be manufactured by Grundfos Pumps
Corporation or equal.
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Project Name
11___-2
Project No.
F.
Safety interlocks:
a. The generator system shall have a customer controlled safety interlock
to shut-down the entire generator system.
b. The chlorine dioxide generator shall cease chemical generation if the
level sensors in the generation chamber or batch holding reservoir fail
to match the operation mode.
G.
The generator system shall include an air bladder system connected to a
carbon filter to control any gas accumulation from the top of the generation
chamber.
H.
All necessary generation and feed equipment, including the precursor
pumps, generation chamber, microprocessor control, overflow batch
product holding tank, off-gassing safety system and product feed pump
shall be integrated in to a single boxed system for simple mounting on a
frame or directly to the wall.
2.02 INTERFACE
A.
The chlorine dioxide generator shall provide an interface through a control
PLC with 4-line plain text lit display with menu-controlled operator
prompting. The control PLC menu interface shall be used for
commissioning, entering operation parameters, rinsing the system and
maintenance.
B.
The control PLC shall be capable of direct connection to chlorine dioxide,
redox (ORP)) or pH measuring cells for control of chlorine dioxide feed
through direct system measurement.
a. The measuring cell for pH, redox or chlorine dioxide measurement
shall be an Aquacell AQC unit with flow over the measurement
probe(s).
b. The measuring cell shall be manufactured by Grundfos Pumps
Corporation or equal.
C.
The generator shall include the following outputs: a 0/4-20mA analog
outputs for pump control and chlorine dioxide measurement and digital
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Project Name
11___-3
Project No.
alarm outputs to include error status, feed chemical tank empty pre-alert
signal and batch product tank dry-run alarm. The feed pump shall be
controlled by either an analog or dry contract control signal.
2.05
OPERATION
A.
The chlorine dioxide generator shall use two chemical pumps to feed
dilute solutions of hydrochloric acid (9%) and sodium chlorite (7.5%).
a. The precursor feed pumps shall be internal motor-driven pumps and
are manufactured by Grundfos Pumps Corporation or equal. Solenoid
driven pumps are not acceptable.
2.06
B.
Precursor chemicals and process water shall be pumped directly to a
reaction chamber for production of chlorine dioxide. The reaction chamber
shall be [950 mL] [1900 mL] in size and include a three position level
sensor to verify precursor feed. Any error detected between the level
sensors and the controller shall cause the generator to cease chlorine
dioxide production.
C.
The chemicals shall undergo a 15 minute reaction time in the reaction
chamber, as controlled by the process controller, and then be fed through
gravity and water make-up flow into the batch, product holding tank
directly beneath the reaction chamber. The batch tank shall be [950mL]
[1900mL] in size and include a level sensor. Any error between the level
sensor and the controller shall cause the generator to cease chlorine
dioxide production.
D.
The generator will consume no more than [0.033 gal/h] [0.065 gal/h] [each
of sodium chlorite and hydrochloric acid solutions and [1.65 gal/h] [3.32
gal/h] of water at maximum capacity.
E.
The generator shall produce chlorine dioxide in a concentration of ca. 2.0
g/L.
F.
Chlorine dioxide solution will be fed from the batch product holding tank to
[the process continuously as required by the system control] [to a batch
tank reservoir system with level controls for future dispersal into the
process] through an integrated product feed pump.
CONTROL
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Project Name
11___-4
Project No.
A.
The generator shall include the capability of several control methods;
including manual, batch, current input, contact input and external target
value control.
1. Manual Control
a. Continuous: Control of the product feed pump from 0 to 100% through
manual input with continuous batch production.
b. Single Batch Dosing: Control of the product feed pump from 0 to 100%
through manual input with a single batch production.
2. Automatic Control
a. Batch: 100% system performance as controlled by an external buffer
product tank, with continuous batch production.
b. Proportional: Control of the product feed pump from 0 to 100% through
a flow-paced proportional control signal and with continuous batch
production. The flow signal can be provided by a contacting head
water meter or flow meter either to the controller or directly to the feed
pump.
c. Set point Control: Control of the product feed pump from 0 to 100%
through a target set point control from the controller as measured from
a chlorine dioxide measuring cell, with continuous batch production.
The set point controller uses the measuring cell values of chlorine
dioxide in the system to change the control signal to the product pump.
d. Combined Control: Control of the product feed pump from 0 to 100%
through both a water flow-paced proportional signal and a chlorine
dioxide set point control, with continuous batch production. The
controller uses signals from a contacting head water meter or flow
meter, and a measuring cell to change the control signal to the product
pump.
PART 3: EXECUTION
3.01
INSTALLATION
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Project Name
11___-5
Project No.
A.
3.02
The equipment shall be installed per the contract documents and
manufacturer’s recommendations, and shall include, but is not limited too:
a.
Foundation, concrete pad or anchor bolts.
b.
Electrical wire, junction boxes or conduit.
c.
Erection and installation.
d.
Interconnecting piping between the generator and the customer
feedpoint.
e.
Piping supports or wall sleeves for the piping.
f.
Water supply and/or necessary pumps.
g.
Supply water pressure regulator if required.
WARRANTY
The equipment/system warranty, unless otherwise stated, shall be
warranted to be free of defects in material and workmanship for a period
of 24 months from the date of installation, but not more than 30 months
from the date of manufacture.
A.
4.01
ACCESSORIES
A. Optional accessories if specified shall include:
1.
2.
3.
4.
5.
6.
Level control inputs and cables
Flow monitor sensor with direct connection to the pump
Back pressure, and relief valves
Foot valves and Injection valves
Analog/Pulse control cables
Alarm Relay cable
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Project Name
11___-6
Project No.