Inditherm Heating Prevents Fat Build-up in Sewerage Sludge Transfer Lines

The Situation

Many STLs suffer from the excessive build-up of fatty deposits on the inside walls of the pipes and associated equipment. This necessitates shutting them down for cleaning on a regular basis, sometimes as often as every 4 weeks.

There is a significant amount of work involved in cleaning out STLs, which is generally done by jetting out using hot water or steam.

This work has a number of consequences:

• The line has to be shut down for several days.
• Scaffolding may be required for the jetting crew.
• Fitters are required for line breakdown and refitting (approximately 1 day for a typical STL).
• The work area and the scaffolding must be cleaned up following the jetting operation.
• In the event that the sludge feeds a digester for a combined heat and power (CHP) plant, the plant may need to be closed down, with the consequent increase in costs and possible loss of revenue.

Build-up of fatty deposits in an unheated 200mm diameter STL

The Solution

The Inditherm heating system eliminates the build-up of fat in STLs and the associated equipment, such as valves and pumps, eliminating the need to close down and clean the lines, along with the cost and health & safety implications.

Heating with Inditherm completely eliminates any build-up, even on bends

Heating System Features

The Inditherm heaters are bespoke and can be fitted around any size of pipe or associated equipment. Each system consists of the low voltage electrical supply and the heating in either fixed or removable form:

• Heating pads under fixed insulation and cladding. The heating pads use Inditherm's CPT encased in a rugged envelope. This is then strapped to the line before being covered by conventional insulation and metal cladding, as shown below. This is ideal for standard pipe runs and is suitable for STLs of any size or length.

Typical configuration of a heated STL with fixed insulation and cladding

Two STLs, one unheated and the other heated with Inditherm under conventional insulation and metal cladding

Removable jacket heaters are constructed using Inditherm's CPT mounted on insulation and then encapsulated in flexible PVC jackets, fitted with appropriate fasters. They are usually made to measure. Fitting removable jackets around pipework and associated equipment is straight-forward and can be completed quickly, minimising time on site. It is normally carried out by Inditherm technicians who will then train site operators how to remove and replace the jackets safely for routine maintenance.

A removable heated jacket around a valve

Specification

• Dimensions: Virtually any size of pipe or associated equipment
• Mains Input Voltage: 115 / 230 / 415 Vac 50Hz, as required
• Output Voltage: 24Vac to all heating pads
• Control Panel: IP rated mild or stainless steel enclosure; rating depends upon application
• Insulation: As required, from 25mm to 100mm in a variety of materials
• Cladding Material: Stainless steel, aluminium, or Plastisol cladding, as required
• Removable Jackets: Fitted to valves, pumps, de-waterers and equipment with complex surface shapes. Heating pads have insulation enclosed in chemical & water resistant covers, secured by hook & loop fasteners and/or removable straps
• Temperature Control: PID thermostat control to ±2°C
• Temp/Current Protection: Internal thermal fuse
• Temperature Range: Ambient up to 90°C

Inditherm Conductive Polymer Technology

Inditherm conductive polymer technology (CPT) is based on a unique carbon-based polymer that generates uniform heat across its entire surface when energised by a low voltage power source.

The Inditherm has fabric-like qualities and flexibility that enable it to be used on pipes and on most industrial components, including items with shapes that are normally difficult to heat. In addition, it is ideal for heating large, flat areas.

The Inditherm polymer is encapsulated in an appropriate, insulated outer cover, depending upon the application. Heated pads can be made to a suitable length to fit between brackets, flanges, etc.

For further information contact Gary Daykin at +44 1709 761000 or gdaykin@indithermplc.com