Automatic Brush Tube Cleaning System for Heat Exchangers | Eqobrush

Automatic Brush Tube Cleaning System

WATCO Group PTE ltd.

Automatic Brush Tube Cleaning System for Shell and Tube Heat Exchangers, Chiller and Steam  Condensers, helps to prevent fouling and scaling of the tubes and to maintain the effectiveness and efficiency of industries and factories power generations without interruption of operations.

System Components | Principle of Operation | Installation Process | Start-up | Maintenance | When Not In Use

The cavemen started brushing their teeth regularly once they found out that “fresh” build-up is easy to remove, as opposed to leaving it untouched and allow scaling. That’s exactly what the tubes of your heat exchanger or condenser need: regular brushing to clean any build-up before scaling sets in.

Eqobrush – Automatic Brush Tube Cleaning System (ATCS) accomplishes exactly that during normal operation of your system. You’re assured that those tubes are kept as pristine as gun barrels, without interruption of operations.

 

EQOBRUSH is designed to fit any heat exchanger or condenser that has a bundle of tubes inside it

Shell and Tube Heat Exchanger

Chiller Condenser

Tube Cleaning Brushes and Other Components of Eqobrush System

Standard brushes are made from PE caps with Stainless Steel wires and nylon bristles for application in water with temperatures up to 60 ᴼC.

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Standard sizes range from 10-24 mm tube diameter.
Depending on the fouling level of the cooling tower water these brushes will last 3-5 years until replacement.
Different materials are available for special applications.

The cleaning function within circular tubes requires a water flow velocity of a minimum of 0.6 m/s at a pressure drop of 0.06 bar. For elliptic tubes, the velocity should exceed 1.0 m/s.

PE baskets are easily removable (and re-usable) from the socket when necessary during inspection or brush replacement.
 

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Locked in operation to secure all brushes at the tube ends. The catch baskets come in different sizes to meet all tube diameters standards.
The connection to the tube is made by cementing or shrinking to the tube ends (depending on tube design).

The special reversing valves are designed in the nominal size from 80 mm to 600 mm for nominal flow rates from 50 m³/h to 3000 m³/h.
 

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The most important parameters for the valve are:
– Security of long-term operation
– Pressure drop
– Low leakage or Cross-over rate of cold water into the hot water stream

The standard operational pressure is 6 bar and a cooling water temperature with a maximum of 50°C. In accordance with the actual operating conditions and water quality, the units will be manufactured from construction steel inclusive coating (standard design) or from stainless steel.
Materials and valve designs for different piping layouts are variable.

Compact multi-functional actuator with end position switches and torque control in IP55 housing. Manual emergency operation possible.

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A combined rotating drive system with worm gear unit. The electric motor drives the shaft of the valve via the worm gear.

Pneumatic actuators or Electric actuators with fail-safe spring return are optional.

The IP55-control panel carries the components required for the automatic operation.
 

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Any cleaning cycle interval from 15 minutes to 24 hours can be set. Switching positions are fixed before delivery.
Additional cleaning-cycles can be initiated via the manual switch.
A built-in counting device registers all cycles completed.

The EQOBRUSH system operates completely independently and does not interfere with other processes. The switchboard therefore does not need to be connected to the overall process control system.

Options

For systems with multiple heat exchangers or chillers we can offer additional options in terms of control and monitoring. 

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– Interface for communication with Building or Process Management System
– Remote monitoring of cleaning cycles and chiller energy consumption

How Tube Cleaning Brushing System Works

EQOBRUSH

How to keep heat exchanger tubes clean using cleaning brushes

The brush cleaning system consists of two catch baskets and one nylon brush for each heat exchanger tube. Both baskets are permanently fitted to the pipe ends and serve to accept the brushes. By reversing the direction of the cooling water flow, the brush is pressed through the tube and at the other end it is accepted by the basket. When the cooling water stream is diverted again in the normal direction, also the brush will return into the catch basket located at the delivery end. The inner walls of the tubes thus being cleaned now eradicating any fouling or scaling.

Why reversal valve, actuator and control panel is part of Eqobrush Cleaning System

The reversal of the water flow direction occurs by means of a reversing valve which can be set to any desired cycle via an electric actuator and control box. The automatic valves of the Eqobrush Automatic Cleaning System reverses the water flow in the heat exchanger every few hours (every 4 to 6 hours) for 30 seconds. Pressure loss is avoided as once the reversion is done and the brushes are positioned in the baskets. This cleaning interval is fixed by our engineers according to the operating conditions and degree of contamination of the cooling medium, but depending on seasons or other influences it may also be changed by the operating personnel.

The cleaning action of the brush makes it possible to remove loose, gelatinous deposits from the internal surface of the tube without any restriction. The hard deposits, tending to adhere more strongly, cannot even get the opportunity to form. Moreover, sludge accumulations or other contamination are precluded, which allows to achieve top performance at all times. There’ll be no more interruptions of operations for mechanical or chemical cleaning.

Installation process

Get Started with Eqobrush

1. Install sockets, baskets and cleaning brushes

The brushes, sockets and baskets cleaning cloth, cement, paper cups and application brushes are all provided with the system components. The cleaning solvent needs to be supplied by the owner.

Recommendations on Using EQOBRUSH

Install after heat exchanger manual cleaning or on a new equipment

It is strongly recommended to install the units only on clean heat exchanger systems, either immediately after manual cleaning or on new equipment.

2. INSTALL FLOW REVERSAL VALVE and Actuator

The bottom or back side of the valve (the side that connects to heat exchanger/condenser) can be installed in the pipe work without extra precautions, while the top or front side of the valve (at the cover flange where actuator is to be installed) the piping MUST BE INSTALLED WITHOUT STRESS OR ANY FORCES ON THE VALVE BODY. We recommend rubber compensators in the piping of valve. The compensators supplied should be installed on the actuator (cooling tower) side of the valve

Recommendations on Using EQOBRUSH

Operate Only With Active EQB-reversing valve

We highly recommend not running the heat exchanger system without activating the reversing valve over periods longer than 12 hours as this may allow calcium deposits to deposit and harden.

Water Inlet Strainer

To remove possible foreign objects obstructing the valve it is necessary to disconnect the piping, hence this requires a stop of the installation. We suggest regular checking to prevent this (mostly caused by defect strainers at the water inlet) from happening.

3. INSTALL PLC CONTROL PANEL

After actuator and position indicator are properly mounted and all wirings are connected according to the diagram, adjust position indicator which controls the initial alignment position of valve inlet/outlet holes and swing box hole of the valve.

PLC will automatically activate every 4 hours to complete a cleaning cycle. It is programmed to record the number of automatic cycles completed (downloadable to PC with specific software)

Recommendations on Using EQOBRUSH

Placement of Control Panel

The EQOBRUSH system can operate completely independent and does not interfere with any of the thermal systems connected to the heat exchanger or condenser. It is therefore not necessary to connect to other operational control systems in use. However, we do strongly recommend installing the control panel in a location where it is clearly visible to the operating staff as to ensure any blinking alarm to be visible.

Start-up

Get Started with Eqobrush

To start up the water system follow the instructions from the chiller / heat exchanger. Make sure the valve and flange connections do not leak and that there are no air pockets in the pipe work. (Install deaeration valves where necessary).

Once the system pump(s) is running for a while, the first cleaning cycles can be activated manually. Monitor the valve behavior during operation and confirm that the swing box runs smoothly. If not, there may still be air pockets in the system. Let the pumps run for a while till all air pockets are filled.

STEP 1

Before electrical activation, the valve should be operated manually to see if the valve travel is free and smooth. Putting down the hand lever and turn the valve by hand into the reversal position and back. If the runway is smooth the panel can be activated.

STEP 2

Set the switch on the actuator to “LOCAL”. Then activate a cleaning cycle by turning the function knob to “close” direction. Once arrived, turn the function knob to “open” direction. The valve travel should be smooth.

STEP 3

Set the switch on the actuator to “REMOTE”. The panel will activate the actuator. Lock the function switch so that it is non‐turntable.

STEP 4

Activate a few manual cleaning cycles by pushing the green function light button on the panel. Also now the valve should run smoothly.
The actuator is fully switched off if the function knob in locked in “STOP” position.

Once the power is activated and the system runs smoothly, every 4 hours there will be an automatic cleaning cycle. The time of the cycle is stored in the PLC history.

Maintenance of Automatic Brush Tube Cleaning System

EQOBRUSH

Brushes and Baskets

The system is maintenance free and runs 1 to 2 years without any attention. Every 2 to 5 years the heat exchanger heads should be opened to check the condition of the pipes, brushes and baskets. Replace internal components if required.

Valve and Actuator

The actual running time of the actuator is quite limited: +/‐ 2 minutes a day or +/‐12 hours per year. An oil replacement in the actuator is advised every 2 years depending on the ambient conditions of the valve/actuator set. Contact WATCO for more details.

When Heat Exchanger Is Not In Use

During periods when Heat Exchanger or Condenser is not in use we recommend to

Keep system filled with water

 Keep Heat Exchanger and Reversing Valve filled with water

Do not stop the reversing valve

Do not stop the reversing valve from moving in its set interval. This will minimize risk of valve getting stuck in its position over prolonged period of time

EqoBrush Automatic Tube Cleaning Brushing System For Heat Exchanger

Eqobrush Automatic Brush Tube Cleaning System

WATCO Group PTE ltd.

Automatic On-line Brush Tube Cleaning Systems for Heat Exchangers and Chiller Condensers have proven their effectiveness on efficiency and energy saving in industry and comfort cooling (HVAC). 
Learn more about the benefits and advantages.