Boiler house

Steam injectors

Local regulations may restrict the use of this product to below the conditions quoted.

In the interests of development and improvement of the product, we reserve the right to change the specification without notice. © Copyright 2014

2.2.5

TI-P401-03

AB Issue 5

INS

Direct Steam Injection Heating Systems

A complete system for boiler feedtank, hot water storage

and other industrial process heating requirements.

Stop valve

5

1

2

Y-type strainer

Dial

thermometer

Principal features:

3

4

• Stainless steel injector for long life

• No moving parts - maintenance free

• Self-acting system requiring no external power supply

• Efficient and economic heating

General description

Spirax Sarco INS direct steam injection heating systems are

designed to inject steam into tanks of water or process liquor to

ensure quiet and efficient heating of the tank contents. The injector

draws in cold liquid, mixes it with the steam within the injector nozzle

and distributes the hot liquid throughout the tank. In many

applications the circulation induced by the injector is an advantage

ensuring thorough mixing and avoiding temperature stratification.

Available system types

INS15, INS20, INS25, INS40, INS50, INS65 and INS80, screwed

BSP (BS 21 parallel) or NPT.

The injectors are for horizontal installation.

The selection of a system depends on the flowrate of steam required

to heat the tank contents and the steam supply pressure to the

control valve.

Boiler feedtank applications

Oxygen must be removed from boiler water if corrosion is to be

prevented. Oxygen can be removed in two ways, either by the use

of oxygen scavenging chemicals or by thermal de-aeration.

The dissolved oxygen content of water:

-

At 20°C is 9 ppm

-

At 60°C is 5 ppm

-

At 90°C is just under 2 ppm.

By heating the boiler feedwater typically to 85 - 90°C to remove most

of the oxygen, and using oxygen scavenging chemicals in the

feedline after the tank, the use of chemicals can be reduced by up

to 75%. Additionally, boiler efficiency may be increased since

blowdown requirements may be lowered. The fitting of a dial

thermometer on the tank is recommended and is available from

Spirax Sarco.

System components

No. Part

1

Control valve

2

Controller and sensor

3

Sensor pocket

4

Horizontal injector

5

Vacuum breaker

Material

Bronze / gunmetal

Brass

Stainless steel

Stainless steel

Brass