Steam Jet Heaters
Inline and in-tank steam jet heaters for direct-contact liquid heating. No moving parts, no packing glands, no lubrication required. Low initial cost and minimal maintenance.
Steam Jet Heaters
Steam Jet Heaters utilize the jet pump principle to mix steam with a cold liquid uniformly. Operation is efficient because the heat in the steam is absorbed by the liquid being heated to approximately 10% of liquid saturation temperature. The jet action produces agitation and circulation, eliminating the need for other equipment to accomplish these functions in most applications.
Basically, all of these have a nozzle or orifice arrangement, a diffuser, and body. In operation, jet heaters use steam (or steam and water under pressure) as the motive force to entrain, mix with, heat, and pump (or circulate) the suction liquid.
Model Series — Operating Specifications
All models heat by direct condensation of steam into the liquid. Liquid enters the motive connection; steam enters the heating/suction connection.
| Model | Heating Process | Max Temp Rise (°F) | Max Flow Heated (GPM) | Steam Press Range (PSIG) | Best For |
|---|---|---|---|---|---|
| MLE | In-line | 180 | 5,000 | Vac – 45 | Low-pressure steam; single-pass; highest steam draw |
| MLH | In-line | 215 | 5,000 | Vac – 120 | High temp rise per pass; single-pass systems |
| ULJ | In-line | 200 | 700 | 0 – 150 | Multi-pass; low liquid pressure drop; recirculating loops |
| TLA | In-tank | 125 | 4,000 | 1 – 140 | Submerged tank heating; agitation included |
Order of largest to smallest temperature rise and pressure drop: MLE → MLH → ULJ. TLA is in-tank only.
How It Works — Three Service Connections
Eductor liquid heaters operate by condensing steam directly into the liquid being heated, ensuring complete transfer of BTUs from the steam to the liquid. The steam gives up its BTUs as it condenses, which also dilutes the motive liquid with condensate. In some cases, the BTUs released allow the unit to discharge to higher pressures than either the motive or suction pressure.
The liquid to be heated enters here under pressure. As it passes through the nozzle, pressure converts to a high-velocity stream that enters the heating chamber. This velocity draws steam into the liquid.
The high-velocity liquid stream draws steam into the heating chamber, lowering pressure and allowing more steam to enter. As steam is entrained, its BTUs are released into the fluid, heating the liquid. The resulting mixture is pushed toward the outlet.
The energies of condensed steam and liquid combine. Unlike other eductor applications, the heater has positive power input on both incoming ports. In high discharge pressure cases, a bypass valve is often required for start-up.
Pipeline Heaters — Principle of Operation
The liquid under pressure attains a high velocity passing through the nozzle. Steam enters through a series of nozzles in the combining tube and an intimate mixing of the liquid and steam occurs in the throat region. The liquid absorbs all of the heat of the steam. Under normal conditions no loss in water pressure occurs. In certain cases, this water can be operated against back pressures higher than either the supply water pressure or steam pressure.
These heaters can eliminate mechanical pumps, resistance or bayonet heaters and containment vessels. These units have a low initial cost, limited moving parts and are easy to install and require little or no maintenance.
Simplex pipeline heaters combine liquid under pressure with steam at a higher pressure. Pressurized liquid enters the heater and flows through an in-line perforated combining tube concentric to the diffuser. Steam enters the heaters and intimately mixes with the liquid in the tube & venturi. The steam completely condenses and heats the liquid. There is no pressure drop across the heater.
Tank Steam Heaters
Tank Steam Heaters are used in vessels where the direct contact of steam with the liquid to be heated is compatible with the process. Tank heaters provide economical heating as well as thorough agitation of the liquid. Tank steam heaters are submerged directly into the liquid to be heated. There is no practical limitation to the volume that can be heated.
Tank steam heaters offer improved performance over conventional sparger pipes and provide more vigorous agitation using fewer pipe openings. The large open suction passages of the tank steam heater accommodate clean liquids as well as slurries.
Steam Jet Heater Operation
Several types of Steam Jet Heaters are available. Although their designs vary, the operation of each is based on the jet operating principles of the jet pump. Typically, a steam jet heater includes an inlet for the liquid to be heated, a steam inlet (suction) where steam is introduced under pressure, and a discharge where the heated liquid and condensed steam leave the heater.
Why JRG/JT Eductors Are Chosen for Heating
Steam Jet Heater Applications
Steam Jet Heaters are commonly found in these industries: food processing, petroleum, dairy, manufacturing, chemical, distilling/brewing, and others.
Inline Heater Applications
Circulating cleaning solutions, pasteurization, producing scalding sprays, sterilization, heating water, blanching, exchanging heat, degreasing, heating slurries, laundering, cooking, pickling, bonderizing, quenching and tempering.
Open Tank Heater Applications
Cooking grain, cooking mash, cooking starch, heating and circulating, mixing.
Model Selection Guide
Use these rules to narrow down the right model before sizing:
Sizing Formulas — Steam Requirement
All eductor heaters heat by condensing steam into the liquid. Use these approximate formulas for most sizing work — the exact BTU/Lb from steam tables changes the result by less than 3%.
| Term | Definition |
|---|---|
| Qs | Steam flow (Lb/Min) |
| Qm | Liquid flow (GPM) |
| 8.33 | Density of water (Lb/Gal) — multiply by actual specific gravity × specific heat if different from 1 |
| ΔT | Temperature rise (°F) |
| 1100 | Approximate BTUs per Lb of steam |
Parameters Required for Sizing
- Liquid type
- Pressure (PSIG)
- Incoming temperature (°F)
- Flow (GPM)
- Desired temperature rise (°F)
- Steam pressure (PSIG)
- Steam quality (saturated or superheated)
- Maximum outlet pressure (PSIG)
- Desired outlet temperature (°F)
Sizing Procedure — MLE / MLH (5 Steps)
Calculate steam required: Qs = Qm × 8.33 × ΔT / 1100.
In the performance table, locate the row for the liquid motive pressure and move across until the temperature rise meets or exceeds the desired ΔT.
Divide the desired motive liquid flow by the tabulated GPM (two lines below the chosen temperature rise) to obtain the Desired S.F. Select the next larger or equal tabulated S.F.
Confirm the steam pressure at that point is ≤ available steam pressure.
Confirm the outlet pressure at that point meets or exceeds the required outlet pressure. Use the "steam off" value for intermittent service.
Worked Example — MLH
Qs = 90 × 8.33 × 65 / 1100 = 44.3 Lb/Min steam
At 60 PSIG / 65°F rise, the 1-½″ unit flows 30 GPM → S.F. = 90 ÷ 30 = 3.0 → select MLH 2-½″ (S.F. 3.17)
Actual performance: ~91.9 GPM liquid · ~49.4 Lb/Min steam · ΔT ≈ 71°F
Sizing Procedure — ULJ (Recirculating / Multi-Pass)
Liquid flow for ULJ is determined by pressure drop (ΔP), not by temperature rise directly.
Calculate steam required: Qs = Qm × 8.33 × ΔT / 1100.
In the ULJ table, locate the liquid pressure row and the steam pressure column ≤ available steam pressure; read the tabulated steam flow.
Desired S.F. = desired Qs ÷ tabulated steam flow. Select the matching or larger S.F.
Calculate pressure drop: ΔP = (Qm ÷ (14.14 × S.F.))². Outlet pressure Po = Pm − ΔP.
Actual ΔT = Qs × 1100 ÷ (Qm × 8.33).
Sizing Procedure — TLA (In-Tank)
Calculate total steam mass required using the formula above (Gal = tank volume, Sg = specific gravity, Sh = specific heat).
Divide by desired heating time (minutes) to obtain Lb/Min required.
If using multiple TLA units, divide by the number of units.
From the TLA Steam Flow table, obtain the tabulated flow at the available steam pressure for the 1-½″ unit.
Desired S.F. = required Lb/Min per unit ÷ tabulated flow. Select the next larger or equal S.F.
Example: Two TLA ¾″ units at 40 PSIG steam heat a given tank volume in approximately 15.5 minutes.
Sizing Factors (S.F.) — MLE, MLH, ULJ, TLA
All performance tables use the 1-½″ unit as the reference (S.F. = 1.00). Multiply tabulated flows by the S.F. for your pipe size.
| Unit Size | ½" | ¾" | 1" | 1-¼" | 1-½" | 2" | 2-½" | 3" | 4" | 6" | 8" | 10" | 12" |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| S.F. | 0.12 | 0.21 | 0.34 | 0.61 | 1 | 1.82 | 3.17 | 5.92 | 11.8 | 24 | 49 | 71 | 123 |
1-½″ is the reference unit (S.F. = 1.00, highlighted). Standard stock sizes ½″–3″ available from inventory.
Heating with Steam
Steam is supplied in a gaseous state. Heat transfer with saturated steam utilizes the latent heat of steam, releasing a large amount of energy as it condenses (changes to the liquid state). The amount of energy released per unit of steam is high (up to 539 kcal/kg, or 970 Btu/lb, and higher with vacuum steam).
Utilizing latent heat (steam heating) for heat transfer is far more effective than utilizing sensible heat (hot water or oil heating), as a much higher amount of energy is released in a shorter period of time.
| Property | Advantage |
|---|---|
| Rapid even heating through latent heat transfer | Improved product quality and productivity |
| Pressure can control temperature | Temperature can be quickly and precisely established |
| High heat transfer coefficient | Smaller required heat transfer surface area, enabling reduced initial equipment outlay |
How Does Steam Provide Stable, Even Heating?
Unlike heat transfer by convection (e.g. hot water), heat transfer by condensation (e.g. steam) does not involve a temperature change. When steam condenses on the heat transfer surface, it passes on its latent heat to the product. The condensate then formed still contains its sensible heat, so it is of the same temperature as the steam from which it was produced. This enables even heating across the whole heat transfer surface.
If the pressure at the heat transfer surface of the equipment is held constant, continuous heating at a constant temperature can take place throughout every part of the heat transfer surface.
On the other hand, with hot water or oil heating, the temperature of the heating medium is reduced as sensible heat is transferred from the heating medium to the product. The temperature gradient is therefore constantly dropping because each unit of heat transferred will also lower the heating medium's temperature. This can result in uneven heating, which may adversely affect the product being heated.
How Does Steam Provide Rapid Heating?
Heat Transfer from Condensation (Steam): The latent heat contained in steam is released the instant steam condenses into the liquid state. The amount of latent heat released is 2 to 5 times greater than the amount of sensible heat available from hot water (saturated water) after condensation. This latent heat is released instantaneously and is transferred through the heat transfer surface to the product being heated. Through condensation, steam naturally flows against the heat transfer surface, helping speed the heating process.
Heat Transfer by Convection (Hot Water and Oil): In contrast, hot water and oil transfer heat by convective heating, which does not involve a change of state. If left to natural convection, heat transfer is extremely slow. Thus, a pump is typically used to create flow against the heat transfer surface to increase the rate of heat transfer. This is known as forced convection heating.
Request a Sizing
Fill out our jet pump application sheet and we'll reply with the recommended size, price & availability.
Jet Pump Application Form Tank Eductor Application FormRelated Pages
Large Inventory
- Jet Pumps in stock ½″–3″ in Carbon Steel, 316SS & Bronze
- Tank Eductors stocked ⅜″–3″ in Carbon Steel & 316SS
- PPL & PVDF Tank Eductors stocked ¼″–1½″ MNPT
You Might Also Need
Related Products
Liquid Jet Pumps
Pump, transfer, or lift liquids. Carbon Steel, 316SS, Bronze. In stock ½″–3″.
Gas Jet Pumps
Evacuate tanks, purge piping, create vacuum. Steam or air motive. 316SS standard.
Tank Mixing Eductors
Full-tank mixing without agitators. Carbon Steel, 316SS, Hastelloy. In stock ⅜″–3″.
What's Next?
Continue Your Research
Sizing Calculator
Estimate flow rates and motive requirements for your application.
Product Selector Wizard
Answer 3 questions and get an instant product recommendation.
Request a Quote
Submit your process conditions and we'll size and price it for you.
Prefer to talk it through? Call 1+201-419-6111