3D TRASAR Automation - Boiler Blowdown Equipment

Transcription

1 3D TRASAR Automation - Boiler Blowdown Equipment Reduces water and fuel costs by eliminating excessive blowdown Provides better program control and boiler reliability by maintaining boiler TDS at the optimum level Reduces operator s time commitment by automatically adjusting the blowdown rate Optimize the performance of scale, deposit, corrosion and blowdown control programs with a single integrated Nalco 3D TRASAR Boiler Automation System. Complete blowdown conductivity probes assembly simplifies installation Indicator on motorized blowdown valve lets you easily determine if the valve is opened or closed Manual over-ride enables blowdown valve operation during a power outage emergency Adjustable, indicating flow control valve permits blowdown rate changes without disassembling piping Figure 1-3D TRASAR Boiler Automation System Description Conductivity controllers are used to control boiler water dissolved solids at a level appropriate for the system s operating pressure and internal treatment chemical dosage. Closely controlling the dissolved solids level not only helps ensure the performance of the treatment program but can also reduce operating costs by helping to optimize boiler blowdown, saving energy and water. Nalco 3D TRASAR boiler automation and control system (Figure 1) utilizes state-of-the-art, patented technology to provide boiler scale and deposit control and pre-boiler corrosion. The system can control boiler blowdown conductivity levels for up to four boilers (one to two of which can use temperature compensating conductivity probes). The 3D TRASAR Boiler Controller can be set up for either intermittent or continuous sampling. A variety of control and measurement options provides the flexibility to optimize blowdown control for most boiler systems. See Bulletin B-950 for additional details. Also available are standalone Boiler Controller Panels (Figure 2). These can control blowdown for up to four boilers (three of which can use temperature compensating conductivity probes) and greatly simplify installation when the boiler blowdown lines are not located close to the feedwater sample taps. In addition to the controller a conductivity probe, an adjustable flow control valve and motorized blowdown valve are required for a complete installation. These must be ordered separately.

2 Boiler Controller Panels Boiler Control Panels include a controller with a blowdown relay box and laptop shelf mounted on a PVC panel. Note: Conductivity calibration solutions are not included with Coiler Controller Panels. They must be ordered separately. Blowdown Control Functions Based on conductivity measurements Continuous or intermittent sampling On/Off, PID or Time-base proportional control Trap sample capability High/low demand sampling schedules Figure 2 Boiler Controller Panel

3 Conductivity Probe Assemblies The conductivity probes are designed to be installed directly into the boiler blowdown line. They are supplied with an iron cross, union and j-box with terminal strip to simplify installation. All probes have ¾ MNPT threads and have a measurement range of ,000 µs/cm. Notes: 1. Probe assemblies with 1 and 1-1/2 crosses utilize a reducer bushing to accommodate a longer ¾ conductivity probe. 2. Use 2-twisted pair, shielded, 22 AWG cable (minimum) for noncompensating probes. Use 4-twisted pair, shielded, 22 AWG cable (minimum) for temperature compensating probes. Figure 3 Conductivity Probe Assembly Maximum Temperature & Pressure Temperature Compensating Process Connection (Cross) Nalco Part Number (Assembly) Nalco Part Number (Probe Only) N 3/4" 060-BDP psig@392 F (17.2 bar@200 C) Y 3/4" 060-BDP100C N 1" 060-BDP N 1-1/2" 060-BDP psig@482 F (41.4 bar@252 C) N 3/4" 060-BDP BP Y 3/4" 060-BDP600C BP600C.88

4 Motorized Ball Valve & Flow Control Valve Packages The packages include a motorized ball valve to effect on/off control of boiler blowdown along with the appropriately sized flow control valve. These economical packages provide a savings over buying the valves separately. Keep in mind that motorized ball valves work differently than solenoid valves. The motor must be energized to open and energized to close. Note: All motorized valves use 115 VAC power. Figure 4 Motorized Ball Valve and Flow Control Valve Package

5 Motorized Ball Valves The motorized blowdown valve is connected to the conductivity controller, which opens or closes the valve in order to maintain the desired level of dissolved solids in the boiler. The standard ball valve is mounted to the standard actuator. The high pressure ball valve is mounted on the high pressure actuator. Actuators These high-torque, heavy-duty reversing actuators rotate from 0º to 90º in several seconds. The spur gear drive train has been designed for severe applications and can withstand stall conditions without suffering gear failure. The heavy-duty aluminum enclosure meets NEMA 4 specifications. It has a thermally bonded ultraviolet-resistant polyester powder coating that is corrosion resistant. Figure 5 Motorized Ball Valves Standard equipment includes a motor with thermal overload protection, stainless steel fasteners, captive cover screws, 300 series stainless steel output drive, spring friction brake, and position indicator. Actuator Specifications Standard High Pressure Torque: 100 In-lb (11.3 Nm) 200 In-lb (22.6 Nm) Cycle Time: 2.5 Seconds 5 Seconds Current Rating Full load = 0.40 Full load = 0.38 (amps): Lock rotor = 0.55 Lock rotor = 0.75 Weight: 7 lb (3.2 kg) 10 lb (4.5 kg) Mounting: Direct Standoff bracket Duty Cycle: 25% Enclosure: NEMA 4 (IP66) Enclosure Thermally bonded polyester powder Coating: Power: 115 VAC, Hz, 1 Ph Motor: Permanent split capacitor with thermal overload protection (160⁰F to 200⁰F based on conditions) Indicator Visual dome style Switches: Snap action SPDT, 250 VAC Lubrication: Grease, permanent, little or no maintenance required Temperature: -40⁰F to 150⁰F (-40⁰C to 65.6⁰C) heater & thermostat required 0⁰F and below

6 Ball Valves Full-port, stainless steel ball valves are ideal for control of boiler blowdown lines. The valve bodies are made CF8M which is a molybdenum bearing alloy that is the cast equivalent of wrought AISI 316 stainless steel. Ball Valve Specifications Standard High Pressure Valve Type: 2-piece, full port 3-piece, full port Valve Body: CF8M CF8M Ball & Stem: 316 SS 316 SS Valve Seat: Teflon PEEK Valve Packing: Teflon Grafoil Figure 6 - Standard ball valve limits Figure 7 - High pressure ball valve limits

7 Flow Control Valves The durable, forged steel flow control valve is used to regulate the blowdown rate and help ensure the iron cross with conductivity probe is completely full with boiler water. It features an indicator scale (number of turns valve is open) to simplify flow rate adjustments. Note: These flow control valves are compatible with both types of motorized ball valves and included in all Motorized Ball Valve & Flow Control Valve Packages. Specifications Valve Type: Class 800 globe valve Body: Forged carbon steel Trim: 13% Cr SS Seat: Hard Faced Scale: Number of turns valve is open Figure 8 Flow Control Valve Turns to Open Valve: 1/2 valve: 3.7 turns 3/4 valve: 5.2 turns 1 valve: 5.2 turns Figure 9 Flow Control Valve Limits

8 To Order Use the Nalco part number in the component specification table when ordering. To be sure this product is compatible with your process contact your local Nalco representative. Selection Guide The boiler water pressure and temperature must be below the limits for the conductivity probes, motorized ball valve and flow control valve. The flow control valve ratings are higher than the motorized valves. So, they can be used with either range of hardware. Select either the Standard conductivity probe and valve package or the High Pressure conductivity probe and valve package that meets the Safe Zone limits. Standard Probe & Valve Package High Pressure Probe & Valve Package Replacement Parts & Accessories Nalco Part Number Description Valve, SS, 1/2"(for 041-BLR006.88) Valve, SS, 3/4"(for 041-BLR007.88) Valve, SS, 1"(for 041-BLR100.88) 041-BLRV06H.88 Valve, SS, 1/2"(FOR 041-BLR006H.88) 041-BLRV07H.88 Valve, SS, 3/4"(FOR 041-BLR007H.88) 060-BJBC J-Box, 3/4 cross, and union (for blowdown sensor assembly) Cable, 2-pair, 22 AWG, shielded (per ft) 001-H Conductivity standard solution, 10,000 µs/cm, 500mL 001-H Conductivity standard solution, 5000 µs/cm, 500mL 460-S Conductivity standard solution, 3000 µs/cm, 1L 460-S Conductivity standard solution, 600 µs/cm, 1L 460-S Conductivity standard solution, 500 µs/cm, 1L 460-S Conductivity standard solution, 200 µs/cm, 1L 500-P Beaker, 800 ml, plastic (3 each)

9 Installation Proper installation and mounting of the conductivity probe and motorized blowdown valve is important. Follow the manufacturer s installation guide as closely as local conditions permit. Refer to Figures 10 and 11 for recommended installation layouts. Locate the motorized blowdown valve away from the wall of the boiler where heat can be excessive. An internal thermal overload switch prohibits operation if the actuator motor temperature exceeds 160 F (135 C). Important Installation Notes: 1. Make sure the minimum water level in the boiler is at least 4-6 inches above the skimmer blowdown line. If the skimmer line is closer to the surface, it is likely that steam will be drawn into the line instead of boiler water. 2. Maintain a 1 inch minimum pipe ID with no flow restrictions from the boiler tap for the skimmer blowdown line to the cross with the electrode. If the ID is reduced below 1 inch before the cross, flashing will occur beyond that point and the conductivity reading will be low and erratic. This will also cause the seals on the motorized ball valve to fail. 3. A manual shut off valve should be installed so the electrode can be removed and cleaned. This should be a full-port valve to avoid a flow restriction. 4. Keep the distance between the tap for the boiler skimmer line to the electrode as short as possible. 5. There MUST be a flow restriction (flow control valve) after the electrode, downstream of the motorized ball valve. This is needed to control the blowdown rate and ensure the piping is always filled with water. Unrestricted flow to a free drain will cause flashing at the electrode or motorized valve.

10 Typical Installation Figure 10 Continuous Sample Blowdown Recommended Installation

11 Figure 11 Timed Sample (Intermittent) Blowdown Recommended Installation

12 Figure 12 - Blowdown Relay Box Field Wiring Figure 13 Motorized Valve Field Wiring