WOODWARD 9904-806

الوصف

The WOODWARD 9904-806 is a mechanical-hydraulic speed droop governor specifically designed for steam turbines. It is a part of the TG-17S (Screw) series, known for its robust mechanical operation and precise screw-based speed adjustment.

WOODWARD 9904-806: Mechanical-Hydraulic Speed Droop Governor (TG-17S, 6000 rpm, CCW Rotation)

The WOODWARD 9904-806 is a self-contained, mechanical-hydraulic control device crucial for the stable operation of small to medium-sized steam turbines. It’s particularly well-suited for applications where consistent speed control with a predictable droop characteristic is required, as opposed to strict isochronous (constant) speed. Its “Screw” designation indicates a precise mechanical interface for speed setting.

Product Overview

The 9904-806 constantly monitors the turbine’s rotational speed and precisely adjusts the steam admission valve to control the turbine’s speed based on the speed droop principle.

• Product Type: Mechanical-Hydraulic Speed Droop Governor
• Manufacturer: Woodward
• Series: TG-17S (Screw-operated)
• Application: Small to medium steam turbines (e.g., driving pumps, compressors, generators).
• Key Feature: Speed droop control (not isochronous).
• Rated Speed: Designed for operation up to 6000 rpm.
• Speed Setting Mechanism: Screw-operated (for fine, manual adjustment).
• Drive Shaft Rotation: Counterclockwise (CCW) rotation.
• Output: 23.7 N·m (17.5 ft-lb) rotary output. (The TG-17 series provides higher work output than the TG-13 series).
• Environmental Certification: ATEX certified (suitable for potentially explosive atmospheres).
• Rated Speed @ 2° Droop: 5860 rpm (a specific configuration point for droop, indicating the speed reduction for a given load increase).

Detailed Product Description

The WOODWARD 9904-806 offers a reliable and cost-effective solution for steam turbine speed control. It’s a key member of the durable and widely recognized TG-17 governor family, which provides higher work output compared to the TG-13 series.

Here’s a breakdown of its functionality and features:

• Mechanical-Hydraulic Operation: This governor is a fully self-contained unit. It uses a drive shaft-driven ball head assembly to accurately sense the turbine’s speed. An internal, shaft-driven oil pump generates the necessary hydraulic pressure (1379 kPa / 200 psi for TG-17 governors, higher than TG-13’s 1034 kPa / 150 psi) to power the internal servomotor, which precisely controls the turbine’s steam admission valve. This robust mechanical-hydraulic design minimizes reliance on external electronic components for its core function.
• Speed Droop Control: The 9904-806 operates on the speed droop principle. This means that as the load on the turbine increases, its speed will slightly decrease in proportion to that load. This characteristic is often desirable in applications that involve load sharing among multiple prime movers or where a slight, predictable speed variation due to load changes is acceptable.
• Direct Turbine Interface: The governor is designed for direct coupling to the steam turbine’s rotor or an auxiliary shaft to receive speed input. Its rotary output shaft then directly connects to the turbine’s steam admission valve, enabling precise regulation of steam flow.
• 6000 rpm Capability: This specific model is optimally configured for turbines operating at higher rotational speeds, up to 6000 rpm. This speed capability is vital for ensuring proper integration and performance with faster-spinning prime movers.
• Screw-Operated Speed Setting: The “S” in TG-17S indicates that the speed setpoint is adjusted via a screw mechanism. This method provides fine, stable, and precise adjustment of the desired turbine speed, making it suitable for applications that don’t require frequent or rapid speed changes.
• Counterclockwise (CCW) Rotation: The 9904-806 specifically features a counterclockwise drive shaft rotation and a corresponding counterclockwise output shaft rotation. This is a critical mechanical specification that ensures correct integration with the turbine’s drive train.
• Higher Work Output: As a TG-17 series governor, it offers a higher work output of 23.7 N·m (17.5 ft-lb). This increased capacity allows it to control larger or more demanding turbine valves compared to the TG-13 series governors.
• Rugged Construction and ATEX Certified: Built for challenging industrial environments, these governors feature a rugged construction and a self-contained oil sump. The ATEX certification confirms its suitability for use in potentially explosive atmospheres, commonly found in many industrial plants like oil & gas facilities or chemical processing plants.

In summary, the 9904-806 is a reliable, robust, and ATEX-certified mechanical-hydraulic governor, ideally suited for high-speed steam turbine applications (up to 6000 rpm) that require precise screw-based speed adjustment and a counterclockwise drive shaft rotation.

Technical Specifications (General)

Typical Applications

The WOODWARD 9904-806 is commonly found in industrial settings utilizing small to medium steam turbines for mechanical drive or power generation, especially in situations where:

• High Speeds are Present: Turbines operating at or around 6000 rpm.
• Higher Work Output is Needed: To operate larger or stiffer turbine control valves.
• Speed Droop Control is Adequate: For applications where load sharing or slight speed variation with load changes is acceptable.
• Mechanical-Hydraulic Simplicity is Preferred: When a robust, self-contained mechanical governor is favored over more complex electronic systems, particularly in hazardous locations.
• Precise, Infrequent Speed Adjustment: Where the screw-based speed setting offers sufficient and stable control.
• Counterclockwise Rotation: The turbine’s mechanical drive interface specifically requires a CCW rotating governor.
• Common Use Cases Include:
  • Pumps: Controlling steam turbines that drive various process pumps.
  • Compressors/Turboexpanders: Regulating the speed of steam turbines used to drive compressors in chemical plants, refineries, or gas processing facilities.
  • Generators: Controlling the speed of steam turbines connected to generators for power generation, often in parallel with other power sources.
  • Fans: Managing steam turbines that power large industrial fans in power plants or other heavy industries.