Algas SDI Blendaire B20 Manual

Models B20 – B1700
Operations & Maintenance
Manual
...Innovative liquid vaporizing and gas mixing solutions
151 South Michigan Street, Seattle, Washington, USA 98108
Tel: [phone] Fax: [phone] Web: www.algas-sdi.com
FILE: MANUAL PN 54702 BLENDAIREII REV 11-30-16.doc

Algas-SDI Operations and Maintenance Manual – P/N – 54702 1-1
1. Introduction
DESCRIPTION The BLENDAIRE is the ALGAS-SDI second generation “parallel pipe” design
Synthetic Natural Gas (SNG) mixer. The BLENDAIRE is designed to mix LPG
vapor and air to simulate the combustion characteristics of natural gas. During
operation, the BLENDAIRE controls & responds to changes in discharge
pressure due to consumption changes. When operating in a piped network, as
network pressure decreases, the SNG flow rate will increase to maintain
pressure. Alternatively, when the network pressure rises, for example as
consumption is reduced, the SNG flow will decrease. The SNG discharge
pressure is established by the LPG regulator installed upstream of the
BLENDAIRE. LPG vapor and air flow rates are measured by flow meters. The
ratio of these two flow rates is then compared to the calculated ratio of flow rates
required to achieve a Wobbe value match to the natural gas being simulated.
Adjustment of the ratio is made by adjusting the air flow only. As the flow of SNG
increases or decreases, the Air Flow Control Valve modulates to maintain the
correct and constant mixing ratio between the LPG and air.
There are two separate flow paths into the BLENDAIRE, one for air and one for
LPG vapor, (See Figure 1).The air inlet piping contains manual shutoff valve,
check valve, flow conditioner, flow meter, pressure transmitter, and a flow control
valve. A required air regulator installed upstream sets the pressure into flow
control valve. The LPG vapor inlet piping contains manual shutoff valve, check
valve, flow conditioner, flow meter, pressure transmitter, and a safety shutoff
valve. A required LPG vapor regulator upstream sets the mixed gas pressure at
the outlet of the BLENDAIRE. The mixed gas line includes a static mixer
section, safety shutoff valve, line pack pressure transmitter, and a manual shutoff
valve (See Figure 2).The line pack pressure transmitter automatically starts the
mixer to an adjustable cut in pressure set point and maintains mixed gas
pressure above this set point until desired line pressure is reached due to
decreased demand.
The BLENDAIRE utilizes a state-of-the-art PLC control technology designed by
Algas-SDI to communicate with sensors and actuators and control the mixing
ratio into the single gas line. Adjustments to operating/control parameters are
performed via the Human Machine Interface (HMI).
The BLENDAIRE achieves extremely high accuracy and stability in the mixing
process. Equally important, operation of the mixer is very simple. Once set up,
the operation is fully automatic requiring minimum human intervention.
In addition to high accuracy and stability, the BLENDAIREmaintains a high level
of safety through the use of automatic safety shut-off valves and closure of the
flow control valve.

Introduction
1-2 Algas-SDI Operations and Maintenance Manual – P/N – 54702
Figure 1 - General Layout
Figure 2 - Component Diagram
Compressed Air Inlet
LPG Vapor Inlet
SNG Outlet
10
6
1
3
7
4
5
8
11
2
6
1
7
5
4
9

Algas-SDI Operations and Maintenance Manual – P/N – 54702 2-3
2. Major Components
1 – FLOW METER
The Flow Meter monitors the volumetric flow of gas through the pipe.
2 - AIR FLOW CONTROL VALVE
The Air Flow Control Valve is used to adjust the flow of air to match the flow of
vapor given a fixed mixing ratio.
3 - MANUAL OUTLET SHUT-OFF VALVE
Manual Shut-Off Valve allows system to be shut off manually at the outlet pipe
and allows the operator to manually control the outlet flow rate when starting the
system.
4 - MANUAL INLET SHUT-OFF VALVE
Allows system to be shut off manually at each inlet pipe to isolate mixer from the
rest of the system.
5 - CHECK VALVE
The Check Valve ensures the flow of gas moves in one direction.
6 - PRESSURE TRANSMITTER
The Pressure Transmitter relays information to the remote control box to prevent
low LPG pressure from forcing lean mixtures.
7 - TEMPERATURE TRANSMITTER
The Temperature Transmitter determines if LPG gas vapor is at safe operating
temperature. The system will shut down if LPG vapor temperature is close to
dewpoint. The chart at the end of this section has the dewpoints for propane, N-
butane and Isobutane.
8 - VAPOR REGULATOR
This regulator sets the downstream mixed gas pressure.
9 - AIR REGULATOR
This regulator sets the air pressure to the flow control valve. A typical differential
is for air to be 7.5 psi above the gas pressure.
10 - AUTOMATIC SAFETY SHUT-OFF VALVE
The Automatic Safety Shut-Off Valve is located at the outlet and vapor inlet and
will automatically close if there is an alarm condition, lack of electricity or if the air
supply is low.
11 -STATIC MIXER
This device induces blending of two separate streams of gases into a consistent
mixture.

Algas-SDI Operations and Maintenance Manual – P/N – 54702 3-5
3. Installation
WARNING
The equipment described in this manual is designed to operate with
LP-gas, a flammable fuel under pressure. The nature of the
application involves inherent hazards that could result in injury.
ONLY a trained and fully qualified person should service this
equipment.
The BLENDAIRE mixer should be installed in an area suitable for its use. The
mixer must be placed on a level pad with no pits or depressions so no gas will
accumulate. Care must be taken in the entire operating area so that LPG is
never near or below its dewpoint in the system at any time. Heat tracing may be
required depending upon location, LPG content and pressure. Mount each
BLENDAIRE unit on a concrete pad strong enough to support its weight (See
equipment drawing).
Every unit is equipped with Auto-Ratio-Adjust, however, a gas quality-measuring
device suitable for the specific operating conditions is required for activation.
The total response time, including sample lag time, should be kept to a minimum.
This can be done by keeping the sample mixed gas line from the pipe to the
instrument as short as possible.
CAUTION
Always consult with local codes and authorities prior to installing
equipment.
The following equipment must be installed for proper operation of the blending
systems:
1. Air supply
2. Vapor supply
3. Mixed gas outlet
4. Instrument air supply
5. Process controls

Installation
3-6 Algas-SDI Operations and Maintenance Manual – P/N – 54702
AIR SUPPLY 1. Air filters may be required on the air supply and instrument air. The user must
determine the cleaning schedule for the filters. Dirty air will cause problems in
the mixing systems. Oil carryover must be less than 2 PPM.Particulates greater
than one micron must be removed. Temperature must be less than 130F.
Dewpoint must be 2 deg. F below the temperature of air entering the mixer.
2. An air dryer for the incoming air supply will be required if water vapor could
condense in the air supply lines.
3. A properly sized first-stage air pressure regulator is required to be installed
upstream of the mixer compressed air inlet. The air supply pipe to this regulator
must not be more than 150 psi.
VAPOR SUPPLY 1. A properly sized first-stage gas supply pressure regulator is required to be
installed upstream of the mixer LPG vapor inlet. This regulator reduces the
operating pressure to approximately 4-10 psi (0.23-0.67 kg/cm2) over desired
mixed gas pressure.
2. If the LPG has a heavy end content, filters must be provided upstream of the
regulator on the vapor inlet pipe to each BLENDAIRE. The user must
determine the cleaning schedule for the filters. A drip leg to drain the heavier
particles should be provided immediately upstream of the first stage
regulator.
3. Heat tracing must be placed over the vapor supply pipes if the ambient
temperature falls within 10°F of the dewpoint of the LPG gas. Electric heat
tracing is preferred with an appropriate controller. All heat tracing must be
suitable for the class of hazardous location in which it is to be installed.
Always consult with the appropriate authorities and all applicable codes.
MIXED GAS OUTLET 1. The temperature of the pipe must be kept above the dewpoint of the air/gas
mixture. Heat tracing over the outlet pipe may be required as well.
2. A check valve must be installed in utility gas line if it is to be connected to
utility gas main into plant.
NOTE
See the LPG gas dew points given in Appendix B
PROCESS CONTROLLERS 1. The BLENDAIRE comes with a local PLC control panel suitable for
hazardous area classification and a remote HMI panel suitable for General
Location.
2. The BLENDAIRE utilizes 4-20mA, 24 VDC to provide power and
communicate with the devices on the mixer. 120VAC is used to control safety
solenoids on the mixer.
3. See wiring Diagram for wire type and required field connections.
INSTRUMENT AIR SUPPLY 1. All safety shutoff valves and flow control valve operate on air and are closed
when the air supply is cut off if a safety shutdown is triggered.
2. An instrument air regulator installed on the mixer must be supplied with
clean, compressed instrument air of minimum 100 psi and no more than 150
psi.

Installation
Algas-SDI Operations and Maintenance Manual – P/N – 54702 3-7
CONFIGURATION OPTIONS
The BLENDAIRE is designed with flexibility in mind. Various configurations allow
inlets and outlet on same side of equipment, on the opposite side of the
equipment and 90 degrees apart from each other.
Figure 3 – Inlets and Outlet on Same Side
Figure 4 – Inlets and Outlet on Opposite Sides
Compressed
Air Inlet
LPG Vapor
Inlet
SNG Outlet
Compressed
Air Inlet
LPG Vapor
Inlet
SNG Outlet

Installation
3-8 Algas-SDI Operations and Maintenance Manual – P/N – 54702
Figure 5 – Inlets and Outlet 90 Degrees Apart
Compressed
Air Inlet
LPG Vapor
Inlet
SNG Outlet

Algas-SDI Operations and Maintenance Manual – P/N – 54702 4-9
4. Start-Up
The following procedures must be performed to each BLENDAIRE system when
they are first installed.
**Refer to Figure 2 – Component Diagram for item numbers.
STARTING THE MIXING SYSTEM (INITIAL ADJUSTMENT)
BLENDAIRE REGULATOR ADJUSTMENT PROCEDURE
1. Make sure all field connections to mixer are completed and leak tested.
Make all electrical connections to mixer per customer drawing and electrical
drawing.
2. Turn on mixer but do not start. Verify through mixer HMI screens all
instruments are connected and reading.
3. Open valves to supply Instrument Air, LPG and AIR to mixer. Keep mixed
gas outlet valve closed.
4. Verify pressure readings on mixer LPG and AIR pressure transmitters match
data sheet.Adjust regulators as needed to set pressure to data sheet
values.
NOTE
The LPG in the system must remain in the gaseous state at all
times. The regulators will not operate properly if there is ANY liquid
in the system. Perform all necessary procedures to eliminate liquid
in the system.
5. Make adjustments to LPG and AIR regulators as required under flowing
conditions.Initial regulator settings can be found in the QA and Data Sheets.
BLENDAIRE MIXING RATIO ADJUSTMENT PROCEDURE
Ratio adjustment is conducted through settings in the HMI on the control panel.
Refer to the BLENDAIRE HMI user manual for ratio adjustment settings.
STARTING THE BLENDER 1. Apply power to the control panel.
2. Depress the START switch on the HMI panel.
3. The instrument air solenoid valve will be actuated and the outlet pressure
should increase to operational pressure.
4. Start the system on a FLARE STACK to dispose of the initial gas.
5. Adjust the mixing ratio or Wobbe Index setpoint of the mixer to the desired
value on the HMI screen.
6. If necessary adjust line pack cut-in and cutoff pressures to desired values.
Refer to the BLENDAIRE HMI user manual for operating set point
adjustments.

Start-Up
4-10 Algas-SDI Operations and Maintenance Manual – P/N – 54702
NOTE
If the start-up is done under cold conditions and liquid has entered
the system, do not restart until all liquid has been removed. If this
condition exists, it is an indication that the system needs adequate
heat tracing.
7. The outlet pressure is maintained by the vapor pressure regulator.
NOTE
Do not change the output pressure from the design system
pressure without changing the safety set points to the
corresponding values
To restart the blender after a safety shutdown, determine and eliminate the
cause of failure and begin the start procedure over.
8. During initial startup of mixer into an uncharged line flow rates can be very
high. Alarms may occur during this charging phase until pressure in the line
starts to equal the pressure outlet set point. Also, during this initial charging,
nuisance tripping of excess flow valves on LPG tank may occur.
9. To reduce the flow rates during initial startup of mixer into an uncharged line,
slowly open the mixed gas outlet valve allowing time for pressure in line to
reach desired setpoint. This will help reduce nuisance alarm tripping during
initial startup.

Algas-SDI Operations and Maintenance Manual – P/N – 54702 5-11
5. Operation
WARNING
The equipment described in this manual is designed to operate with
LP-gas, a flammable fuel under pressure. The nature of the
application involves inherent hazards that could result in injury.
ONLY a trained and fully qualified person should service this
equipment.
SAFETY OPERATING GUIDELINES
The process control panel monitors the following safety functions:
1. Regulated AIR pressure upstream of the Air Flow Control Valve.
2. Regulated LPG vapor pressure upstream of the Vapor Safety Shutoff Valve.
3. Air and LPG Vapor flow rates.
4. Calculated gas / air mix ratio.
5. Wobbe Index or specific gravity from Gas Quality Feedback Device.
SHUTTING DOWN THE BLENDER
1. Push the STOP button on the HMI panel or local control panel.
2. Close the outlet valve.
3. If the unit is to be serviced perform the following:
a. Close the air inlet isolation valve and the vapor inlet isolation valve, and
instrument air inlet isolation valve.
b. Disconnect the power supply to the BLENDAIRE.
c. Safely vent all residual pressure in both inlet spools and mixed gas
spool.

Algas-SDI Operations and Maintenance Manual – P/N – 54702 6-13
6. Maintenance
CAUTION
Turn off the LPG gas inlet valve to the mixer before performing any
maintenance or repairs.
CAUTION
Before performing any work on the blender, follow all safety
procedures for LPG gas; make sure there are no open flames or
electrical sparks, and wear appropriate clothing. Turn off all
electrical power to the mixer.

Maintenance
6-14 Algas-SDI Operations and Maintenance Manual – P/N – 54702
Blendaire Maintenance Schedule
DESCRIPTION FIRST MONTH EVERY MONTH EVERY
6 MONTHS
EVERY YEAR EVERY
2 YEARS
Flow Meters
Inspect housing
seals & verify
they’re in good
condition
Replace housing
seals
Flow Control
Valves Perform visual
inspection & verify
operation Rebuild actuator
Replace main
valve seal
Regulators Inspect and
clean lines. Clean upper body Clean and
re-build
Safety Valve Perform visual inspection & verify
operation Rebuild actuator
Replace main
valve seal
Pressure
Transmitters Re-calibrate &
verify operation
Re-calibrate &
verify operation;
replace as
necessary
PLC Controller
Circuits Perform visual
inspection & verify
operation
PLC Controller
Safeties Check. Perform visual
inspection & verify
operation
Solenoid Valve Perform visual
inspection & verify
operation Clean valve Rebuild valve
Control Lines Clean and purge

Algas-SDI Operations and Maintenance Manual – P/N – 54702 7-15
7. Troubleshooting
PROBLEM CAUSE SOLUTION
Mixer shuts down on high air
pressure First-stage air regulators are set too
high or are malfunctioning.
Reduce air pressure setting or
check/repair/replace first-stage
air regulator
Mixer shuts down on high gas
pressure First-stage gas regulators are set too
high or are malfunctioning.
Reduce gas pressure setting or
check/repair/replace first-stage
gas regulator
Mixer shuts down on low air
pressure
Air compressor is turned off Turn the air compressor on and
ensure proper operation
First-stage air regulator is set too low
or is malfunctioning
Increase air pressure setting or
check/repair/replace first-stage
gas regulator
Air inlet shut-off valve is closed Open the valve
Mixer is overdrawn on startup Open mixed gas outlet valve
slowly on initial start up
Mixer shuts down on low gas
pressure
First-stage gas regulator is set too low
or is malfunctioning
Increase gas pressure setting
or check/repair/replace first-
stage gas regulator
The pump pressure to the vaporizer is
low or pump isn’t functioning Check pump operation and incoming lines
Vaporizer outlet valve is closed Open the valve
Gas inlet shut-off valve is closed Open the valve
Vaporizer shuts down on safety or is
not up to temperature Refer to vaporizer O&M to ensure proper operation
Mixer is overdrawn on startup Open mixed gas outlet valve
slowly on initial start up
Safety shut off valves don’t
open on start
Instrument air pressure loss
Ensure instrument air supply
valve is open and regulator
pressure setting matches
datasheet
Safety solenoid valves malfunctioning. Check wiring and/or repair
solenoid valve(s)
Mixer shuts down on
instrument under range or
over range
Bad connection between instrument
and PLC control box
Check all wiring between
instrument and tighten any
loose connections
Instrument failed Check instrument and
repair/replace as necessary