Best steam economy option for Raw Juice Heating in sugar industry

 Good Approach for Getting Raw Juice Temperature In the View of Energy Saving Concept

Raw juice heating is the first step in the Sugar Process House. The Raw juice temperature is raised to 70–75°C before clarification. To achieve this temperature, the juice is heated in two or three stages using different types of heaters, such as tubular heaters, direct contact heaters, and plate-type heaters, with different heating media. In this article, we discuss the best approach for raw juice heating and the guidelines for achieving better performance of a juice heater with a vapour jacket.

Use of vapour line juice heater for raw juice 1^st   stage heating with lost evaporator  body vapour

1. In the concept of waste heat recovery, the vapour line juice heater is one of the most important  equipment. Here, raw juice can be heated up to 45 to 55^oC .
2. In vapour line juice heater, the heat transfer coefficient is very high when compared to a dead-end type juice heater due to its dynamic vapour effect.
3. Providing one valve or damper arrangement with an auto control system in between VLJH and condenser is also beneficial to achieve good temperature approach. (Easy to perceive for this concept, think about –  consider 5^th body calendria; here provide NCG lines only for vacuum creation, meaning total 4^th vapour condensed in 5^th calendria and remaining uncondensable gases removed purpose we provide pipe lines )
4. While maintaining 5^th body temperature by using condenser automation, it will be helpful to constantly maintain syrup brix and get the maximum temperature of raw juice in VLJH. And also helpful to reduce load on condenser.

Raw juice heating by  Condensate heater for  2^nd stage.

1. The condensate temperature is getting up to 80 °C after the flash cigar system, but our process hot water requirement is between 60 to 65^o. So this excess heat energy is used for heating the raw juice 2^nd
2. Generally, horizontal type juice heaters are used for this heating; here, raw juice temperature rises up to 10 to 15^oC
3. In the condensate heater design criteria, the duplex type heater design is one of the most efficient types of heaters. In the duplex design, the heat transfer coefficient is very high when compared to normal horizontal type heaters. So, in duplex design, the heating surface requirement is less when compared to other types of tubular heaters.
4. In Duplex heater design, flexibility is very high for installing standby heaters and also increasing its capacity. ( i.e with less investment, we can provide standby heaters, and for the existing  heater, we can easily increase the heating surface )

Use a tubular heater with dynamic effect on 4^th vapour for raw juice final heating.

1.  Generally, dead-end and dynamic type tubular heaters are used in the sugar industry. In the dynamic effect, the heat transfer coefficient is high when compare to dead end type heater and also getting the temperature approach in dynamic effect upto 5 to 6^o So that 4^th vapour is sufficient for getting raw juice final temperature.
2. When comparing Direct Contact heater(DCH) & tubular heater for final raw juice heating with same vapour bleeding, tubular is one of the good options regarding steam economy because while using  DCH, getting the extra condensate load on evaporator set.

Guidelines for Better Performance of a Juice Heater with Vapour Jacket

To achieve efficient heating and better performance, follow these design guidelines:

• Keep the vapour jacket in the upper one-third of the tube height.
• Maintain a minimum gap of 1000 mm between the top tube plate and the vapour jacket. This helps remove light non-condensable gases effectively and prevents uncondensed steam from accumulating.
• Keep the vapour slot width between 40 mm and 50 mm.
• The total vapour slot area should not exceed 1.25 times the vapour inlet area.
• The jacket cross-sectional area (Jacket Width × Jacket Height) should be about 50% of the vapour inlet area.
• The vapour inlet should enter the jacket at a right angle for proper steam distribution.
• Do not use a tangential vapour inlet, as it may reduce heating efficiency.
• Position the vent points 15–20 mm below the top tube plate to ensure effective removal of non-condensable gases.

Some Related Articles:

Juice Defecator and Juice Sulphitor Design Criteria | Online Calculator |  Design Calculation of Juice Defecator and Sulphitor with online calculator.

Juice Sulphitation Process | Methods of Sugar Cane Juice Sulphitation | Reactions and methods of sugar cane juice sulphitation process.

Sulphur Melter | Sulphur Melting process in sugar processing industry

Flash Vapour Calculation | Flash Vapour Recovery Vessel Design Calculation. Condensate flash vapour recovery system calculation with example.

Heat Transfer Coefficient of Liquid -Liquid Tubular Heater Calculation| HTC | How to find Condensate Juice Heater Heat Transfer Coefficient Calculation.

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